The purpose of the linkage analysis/data management core is to provide the necessary analytical support to the separate research projects dealing with mapping the human genome. As part of this support, general assistance with the design and management of information on DNA and other genetic markers in family data will be provided. However, the bulk of the activities of the core will involve statistical analysis of both 2 point and multipoint linkage data. This will include studies of both autosomal and X-linked recombination. Both standard linkage programs and specialized mapping programs will be used. The results of this type of linkage analysis will be used to determine both the order of genetic loci and the map distances between them. The majority of the various analyses will be carried out on a microcomputer linked into the Ethernet system at the Johns Hopkins Medical Institutions. The unanswered question of the impact of interference of genetic recombination in mapping the human genome demands further investigation. To accomplish this, the linkage analysis core will carry out additional research involving computer simulation of family data. Results of these simulation studies will determine statistical power to detect different levels of interference over a range of genetic distances using sample similar to those actually collected by the participating research projects. Since the level of interference has not yet been established for humans, these results will have both practical and theoretical value.